Fig 2: Feprazone reduced the expressions of p53 and p21 in IL-1ß-challenged C-28/I2 chondrocytes. Cells were stimulated with IL-1ß (10 ng/mL) in the presence or absence of Feprazone (20 µM). (A) mRNAs of PAI-1 and p21 and (B) proteins of PAI-1 and p21 (n = 5; ###, P < 0.001 vs the vehicle group; &, P < 0.05 vs the IL-1ß group; &&, P < 0.01 vs the IL-1ß group).

Fig 3: CAFs but not IGF-1 increase PAI-1 expression in cancer cells(A) MDA-MB-231 spheroids were culture alone or in presence of CAFs or IGF-1 [50 nM] for 72 h and assayed for SERPINE1 (PAI1) expression by RT-PCR. (B) MDA-MB-231 cell spheroid were cultured alone or in presence of CAFs, IGF-1 [50 nM] and/or Y27632 [10 µM] for 72 h and immunoblotted for PAI-1 and ß-actin as loading control. HUVECs were used as a positive control for PAI-1 expression. (C–D) Effect of PAI-1 inhibition on scattering and invasion of MDA-MB-231 cells in a collagen gel. MDA-MB-231 spheroids cultured with or without CAF2 in a collagen gel over a 7-day period in absence or in presence of 10 µM of geodin. (E) Effect of PAI-1 inhibition on RhoA pathway activation in MDA-MB-231 cells: MDA-MB-231 cells were cultured alone or in presence of CAF2 in absence or presence of 10 µM of geodin and assayed for RhoA activation by RhoA-GTP pulldown assay and immunobloted for phospho-MLC (Thr18/Ser19). Data expressed as mean ± SEM. *p = 0.05, **p = 0.01, ***p = 0.001, ****p = 0.0001.

Fig 4: Proposed model for the role of IL-6 in the induction of postoperative adhesion formation. Upon surgery-induced injury, serosa-resident natural killer T (NKT) cells produce IFN-?, thereby inducing PAI-1, which in turn facilitates fibrin deposition by preventing fibrin degradation as shown previously7. Subsequently, mesothelial cells produce CXCL2 and IL-6, which recruit and activate neutrophils, respectively. The neutrophils produce TNF-a in response to IL-6. Both mesothelial cells and neutrophils produce TNF-a in response to TNF-a. Thus, IL-6 signaling plays a central role in activating the TNF-a-amplifying positive-feedback circuits. The final steps of the initiation of adhesion formation occur when TNF-a induces neutrophils, but not mesothelial cells, to produce TGF-ß1. TGF-ß1 subsequently activates mesothelial cells to transdifferentiate into myofibroblasts that produce fibrosis-promoting molecules such as collagen.

Fig 5: Gene set enrichment analysis (GSEA) enriched Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), and BIOCART pathways in the GSE2240 dataset of SERPINE1 (PAI-1) and decorin (DCN) expression.(A–C) SERPINE1. (D–F) DCN.